Investigation of ethanol-peptide and water-peptide interactions through intermolecular nuclear overhauser effects and molecular dynamics simulations.

摘要: Molecular dynamics simulations have been used to explore solvent-solute intermolecular nuclear Overhauser effects (NOEs) on NMR (nuclear magnetic resonance) signals of [val5]angiotensin dissolved in 35% ethanol-water (v/v). Consideration chemical shift, coupling constant and intramolecular NOE data suggest that conformations the peptide are adequately sampled by up 0.6 μs duration. Calculated cross relaxation terms at 0 25 °C compared experimental values predicted using a particulate model solvent. Many calculated solvent NOEs agreement with results; disagreements particularly striking for hydrogens Phe8 residue peptide. Calculations show individual molecules either component can spend many ns association but dipolar interactions within such complex account only few percent an observed rate. Most parts interact selectively ethanol. Diffusion both components is slowed when they close Solvent-solute acetic acid same obtained from agree experiment. Preferential largely absent, as this solute diffusion rates.